It seems implausible that a building complex as large as the Forbidden City took only 15 years to construct, without the help of industrial machinery and earth-moving equipment – until it becomes clear that about one million people were involved in the enterprise. It is also hard to imagine how it was possible to unite a million workers to produce a set of buildings reflecting a unified vision. Evidently it was done, as the structures themselves bear witness. China's great power rests in its ability to harness a collective will in order to accomplish things that would be unimaginable for an individual and beyond the dreams of ordinary kings.

The Forbidden City is not only the product of a collective will; it also held in place the organizing system, or collective organism, that ran China for 500 years and only stopped operating as intended with the revolution of 1949, when the communists took over. (The emperor was part of the superorganism, but only part, and without the rest of it in place he would not have had any significant power.) It was established by Zhu Ti (1360–1424), the third emperor of the Ming Dynasty, who was also known as the Yongle Emperor (yongle means ‘endless happiness’). Zhu Ti's systematizing mental approach is also evident in the Yongle Encyclopedia, a great scholarly project in which he aimed to bring together everything that was known. It ran to about 1,200 handwritten volumes. Duplicate copies were made, but most of them perished by fire in 1900, and the original vanished long ago.

Lying at the heart of Beijing, the Forbidden City is isolated by a broad moat 52 metres (171 feet) wide and 6 metres (20 feet) deep with four causeways across it, one on each side of the rectangular plan. There is a tower at each corner, with multiple sloping roofs, and massively thick walls, built with a core of rammed earth and faced with layers of fired bricks. Within the defensive wall, obscured from public view, are a thousand buildings that once housed the innermost machinery of state.

The largest buildings are placed on axis on a shared podium, approached by flights of steps. (The section drawing opposite is taken through the podium.) These were the buildings where the Ming emperors held court and where ceremonials took place. The largest of them, the Hall of Supreme Harmony, has been rebuilt many times.

Dating from the late seventeenth century, the current hall is thought to be about half the size of the original. It is nevertheless the largest timber building to survive from the days of imperial China. The Imperial Dragon Throne was there, surrounded by carved and gilded dragons. The slightly smaller hall to the north (on the left of the section drawing) was the Hall of Preserving Harmony, used for rehearsing the ceremonies that would be enacted in the Hall of Supreme Harmony. Between them was a hall where the emperor could rest.

North of these large ceremonial halls, the buildings are on a smaller scale. The next group of three structures on axis, surrounded by a wall that creates a courtyard, was the emperor's domestic domain, including the Palace of Heavenly Purity and other palace buildings. This was the innermost part of the empire, with many layers of walls around it, protecting the emperor, who had the title Son of Heaven, from contact with the mundane world. It was a life of the highest imaginable privilege, but there was little freedom. Each rank of servant had its own system of rules and codes of behaviour, as did the emperor himself. The emperor had the ultimate power at the heart of this great machine, which kept him safe, but which was also the most comfortable of prisons.